CHEM 1211 Lecture Notes - Lecture 1: Scientific Notation, Significant Figures, Decimal Mark

• School: Northeastern University
• Department: Chemistry & Chemical Biology
• Course: CHEM 1211
• Professor: Vasiliki Lykourinou

Document Summary

Concise and applicable statement of a fundamental scientific principle. Law of definite proportions: principle that compounds always contain the same proportion of their component elements. Law of constant composition: principle that all samples of a particular compound have the same elemental composition no matter their source: example: water is h2o whether it is from ocean or rain or steam. Law of multiple proportions: principle that an element may combine in different ratios with another element forming different compounds: example: co (carbon monoxide) vs. co2 (carbon dioxide, scientific theory: Well-substantiated explanation of some aspect of the natural world, based on facts that have been repeatedly confirmed through observation and experiment. (cid:862)(cid:1012)(cid:1013)(cid:1007) steps o(cid:374) washi(cid:374)gto(cid:374) mo(cid:374)u(cid:373)e(cid:374)t(cid:863: uncertain: There is uncertainty in the last number reported! 5% difference for precision and accuracy: precision: The reproducibility of a measurement or the agreement between values. Deviation: measure of the amount of variation in a series of values, accuracy: Closeness of measured value to true value.